The initiating event, which is the first step in the establishment of risk-based accident scenarios, was derived by master logic diagram (MLD) method based on the fault tree analysis (FTA), and then the risk-based accident scenarios were developed by the event tree analysis (ETA) through the derived initiating events. The main initiating events led to the arbitrary operational accident: the dropping of a drum and fire were derived from the MLD method. Consequently, based on two main initiating events, four heading events were derived. and then the 12 risk-based accident scenarios concerning the LILW management in the temporary storage facility were finally established by the ETA method. Crown Copyright (C) 2008 Published by Elsevier Ltd. All rights reserved.